The invention relates to a photoconductive coating, especially for electro-photographic purposes.
Among the materials proposed for the production of electro-photographic coatings, selenium occupies a special place by reason of its physical and technological suitability as regards the range of use.
Nevertheless electro-photographic selenium coatings have three main drawbacks. Firstly in general they are not usable without limitations for both charging polarities, secondly their spectral sensitivity does not extend far enough into the red for a series of applications and thirdly both above a relatively low temperature (70.degree. to 80.degree.C.) and under the action of particular physical and chemical conditions, accelerated crystallisation must be expected, whereby the coatings become useless.
It is the purpose of the invention to avoid these disadvantages.
The object of the invention is to produce a photoconductive coating capable of bipolar charging which has an extended spectral sensitivity and a high thermal and chemical stability.